The project is for the preparation of known chemicals and bulk drugs which are needed by the Program for clinical use. The compounds selected for preparation are not readily available in the quality or quantities required from the original supplier or on the open market. This project is part of the DTP's program to procure bulk chemicals and drugs for the treatment of AIDS and the study of drug action. This project provides the means to obtain nearly any type of chemical compound and the ability to provide large quantities of very high purity drugs. Assignments of materials for preparation will originate with the Pharmaceutical Resources Branch, NCI and will involve a wide variety of chemical structures. Many of the preparations will involve a wide variety of chemical structures. Many of the preparations will involve multi-step sequences and all materials prepared will be fully characterized. Solubility and stability studies and cost data will be provided upon request.